Area code 443: Maryland
Area code 443 is a US state area code for Maryland, on Eastern Time. It has 785 prefixes in service across 81 rate centers, the largest being Baltimore, Annapolis and Towson. It shares its area with 410 and 667, so local numbers there can start with any of them. Local calls there take 10 digits.
Local time in area code 443
America/New_York
Prefixes in service
785 of 792 possible
81 rate centers
Area code 443 facts
| Location | Maryland, United States |
|---|---|
| Time zone | Eastern Time |
| Overlays | 410, 667 |
| Overlay of | 410 |
| In service since | June 1, 1997 |
| Local calls | 10 digits; toll calls 1 + 10 digits |
| Carrier | Not shown. An area code is where a number was issued; numbers port between carriers. Check line type |
Which cities and towns use area code 443?
NANPA records each prefix against a rate center, the local billing area a number belongs to, usually named after its main town. These are the 443 rate centers with the most prefixes in service. 69 smaller ones aren't listed.
| Rate center | Prefixes |
|---|---|
| Baltimore | 185 |
| Annapolis | 39 |
| Towson | 33 |
| Columbia | 31 |
| Glen Burnie | 26 |
| Catonsville | 22 |
| Pikesville | 21 |
| Salisbury | 20 |
| Bel Air | 19 |
| Westminster | 15 |
| Aberdeen | 15 |
| Elkton | 14 |
Source: NANPA central office code assignments, file dated 10/17/2026. Each prefix holds up to 10,000 numbers.
How do I dial a 443 number?
NANPA's dialling plan for 443: local calls inside the code take 10 digits, toll calls 1 + 10 digits. From another area code, dial 1 first. From abroad, use +1. The examples use 555-0147, from a range reserved for fictional numbers.
| Local call inside 443 | 443-555-0147 |
|---|---|
| From another US or Canadian area code | 1-443-555-0147 |
| From outside North America | +1 443 555 0147 |
| E.164, for CRMs and SMS tools | +14435550147 |
When did area code 443 start?
Area code 443 went into service on June 1, 1997 as an overlay of 410. Today 443, 410 and 667 cover the same area as an overlay, which is why 10-digit dialling is needed for local calls there.
Tools for 443 numbers
- Area code lookup
Look up any code or a whole list of numbers, or find the codes for a state or city.
- Area code time zone
Local time for a list of numbers, with a callable-now flag.
- NPA-NXX lookup
Rate center and state for one prefix, a level below the area code.
- TCPA calling hours checker
Whether it's inside the federal 8 a.m. to 9 p.m. calling window there now.
Next step
A 443 number tells you where it was issued, not what it is now.
Mobiles, landlines and VoIP lines share area codes, and numbers move between carriers. A live line-type and carrier lookup on every number in your list says which is which, and that decides which calling and texting rules apply. It's in the Email + Phone plan.
- Drop your list as a CSV
- See its rows, duplicates and bad formats, free
- 100 free email checks when you sign in with Google, no card
Ready to verify now? See the Email + Phone plan
Area code 443 questions
- What state is area code 443?
- Area code 443 is in Maryland, United States. Its largest rate centers by number of prefixes are Baltimore, Annapolis, Towson, Columbia and Glen Burnie.
- What time zone is area code 443 in?
- Eastern Time.
- What area codes overlay 443?
- 410 and 667. An overlay adds a new code to the same area instead of splitting it, so neighbours can have different area codes and local calls need 10 digits.
- When did area code 443 start?
- Area code 443 went into service on June 1, 1997 as an overlay of 410.
- Is a 443 number a cell phone or a landline?
- The area code can't tell you. In the US and Canada mobiles, landlines and VoIP lines share area codes and prefixes, and numbers move between carriers and line types. Only a live line-type lookup answers it for one number.
- How many phone numbers does area code 443 have?
- 785 of its 792 possible prefixes are in service, and each prefix holds up to 10,000 numbers. That counts prefixes assigned to carriers, not numbers in use.
Other area codes in Maryland
Sources
Location, overlays, in-service date and dialling plan: NANPA NPA database, file dated 10/16/2026. Prefixes and rate centers: NANPA central office code assignments, 10/17/2026. Time zones mapped to the IANA time zone database. By the SimpleVerifier Team; how we build these pages.